Table 2 Distribution of the terms according to the classes in PeriO

object

cell

96

cell part

4

extended organism

81

living organism

71

medical material

13

molecule

bacterial molecule

72

chemical drug

227

human molecule

508

object aggregate

molecule aggregate

27

organism aggregate

2

realized entity

disposition

disease

109

process

bodily process

molecular pathogenesis of periodontitis

79

physical process

2

treatment

medical treatment for periodontitis

56

Total

1,347